There have been numerous previous proposals for ballistic vests and other protective armour that can be constructed so as to stop projectiles from most guns without injuring the wearer yet providing a construction that is light enough so that it can be conveniently worn. While some of such prior art proposals, such as shown in U.S. Pat. No. 3,891,996, have been moderately successful in accomplishing such goals, there still is a need to provide a ballistic vest that will comply fully with all of the requirements considered desirable for widespread acceptance by policemen, civilian oriented protective agencies, and the like.
The vest as shown in U.S. Pat. No. 3,891,996 utilized sheets of aramid fiber for the basic construction of the vest, the aramid fiber providing exceptional strength per unit weight, and allowing a vest to be constructed that had excellent stopping power while still being light enough for normal use. In the practical application of such vests, the aramid fiber was densely woven and held rather tightly in place by tight stitching. It has been found, however, that when aramid fiber is maintained in a relatively unrestricted state the cutting resistance of the aramid fiber is greatly increased, and by using particular loosely woven aramid material arrangements the weight and thickness of the vest can be significantly reduced while still maintaining appropriate fiber density for ballistics protection.
According to the present invention, a vest is provided that utilizes as the basic components thereof a plurality of layers of double woven cloth of loosely woven aramid fiber. The layers of double woven cloth are stitched together at predetermined spaced intervals by selected yarns passing from one cloth sheet to the other, such as shown in U.S. Pat. No. 2,816,578 (the disclosure of which is hereby incorporated by reference herein). Each layer of double woven cloth so constructed will preferably have a 34 by 34 construction, although other constructions that provide for low weight and thickness while still maintaining sufficient fiber density for ballistics protection may be utilized. Means are also provided in the vest according to the invention to provide a degree of elongation to the total vest configuration, providing surfaces on which the layers of double woven cloth of loosely woven aramid fiber can slide in response to projectile impact. Such elongation providing means having synergistic effect on the total composition, giving a somewhat elastic property to the vest allowing it to give with the bullet during the absorption of the kinetic energy thereof, and then recover with a fair degree of rapidity to approximately its original configuration. Layers of nylon film or fabric interspersed with the layers of double woven cloth of aramid fiber provide the necessary elongation characteristics.
The layers of double woven cloth of aramid fiber and the interspersed layers of nylon film or fabric are bar tacked together by short lines of stitches, such bar tacking providing means for loosely maintaining the layers of double woven cloth and nylon film or fabric together so that shape and flexibility are maintained. Such bar tacking gives the vest the minimum rigidity to hold the layers in place and prevent any substantial lateral movement while still allowing sufficient movement of the aramid fiber so that it will not easily shear. While the bar tacking does provide minimum rigidity, in order to maintain vest configuration and prevent collapse of the vest over long periods of time it is preferable to provide a plurality of material layers which help maintain the configuration and prevent collapse. Such layers may comprise sheets of ballistic nylon cloth or tightly woven aramid fiber, both of which are shown in U.S. Pat. No. 3,891,996. The entire vest is disposed in a water-tight envelope, such as a heat sealable polyurethane coated nylon substrate material. While water-tightness is desirable, there is no need for the envelope to be airtight and in order to minimize costs the envelope preferably is airpermeable.
Vests constructed according to the present invention are lightweight, relatively thin, will maintain their integrity over long periods of time, and are capable of fully complying with standard protection criteria for 0.22 calibre, 0.38 calibre, 9 millimeter, and 0.357 magnum (both high and low velocity) projectiles.
It is the primary object of the present invention to provide improve lightweight ballistic vests, and like protective armour. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.